You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
57 lines
2.0 KiB
57 lines
2.0 KiB
From: David Howells <dhowells@redhat.com>
|
|
Date: Fri, 10 Sep 2010 08:59:51 +0000 (+0100)
|
|
Subject: KEYS: Fix bug in keyctl_session_to_parent() if parent has no session
|
|
keyring
|
|
Git-commit: 3d96406c7da1ed5811ea52a3b0905f4f0e295376
|
|
Patch-mainline: 2.6.36-rc4
|
|
References: CVE-2010-2960 bnc#634637
|
|
Introduced-by: 2.6.32
|
|
|
|
KEYS: Fix bug in keyctl_session_to_parent() if parent has no session keyring
|
|
|
|
Fix a bug in keyctl_session_to_parent() whereby it tries to check the ownership
|
|
of the parent process's session keyring whether or not the parent has a session
|
|
keyring [CVE-2010-2960].
|
|
|
|
This results in the following oops:
|
|
|
|
BUG: unable to handle kernel NULL pointer dereference at 00000000000000a0
|
|
IP: [<ffffffff811ae4dd>] keyctl_session_to_parent+0x251/0x443
|
|
...
|
|
Call Trace:
|
|
[<ffffffff811ae2f3>] ? keyctl_session_to_parent+0x67/0x443
|
|
[<ffffffff8109d286>] ? __do_fault+0x24b/0x3d0
|
|
[<ffffffff811af98c>] sys_keyctl+0xb4/0xb8
|
|
[<ffffffff81001eab>] system_call_fastpath+0x16/0x1b
|
|
|
|
if the parent process has no session keyring.
|
|
|
|
If the system is using pam_keyinit then it mostly protected against this as all
|
|
processes derived from a login will have inherited the session keyring created
|
|
by pam_keyinit during the log in procedure.
|
|
|
|
To test this, pam_keyinit calls need to be commented out in /etc/pam.d/.
|
|
|
|
Reported-by: Tavis Ormandy <taviso@cmpxchg8b.com>
|
|
Signed-off-by: David Howells <dhowells@redhat.com>
|
|
Acked-by: Tavis Ormandy <taviso@cmpxchg8b.com>
|
|
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
Acked-by: Jeff Mahoney <jeffm@suse.com>
|
|
---
|
|
|
|
security/keys/keyctl.c | 3 ++-
|
|
1 file changed, 2 insertions(+), 1 deletion(-)
|
|
|
|
--- a/security/keys/keyctl.c
|
|
+++ b/security/keys/keyctl.c
|
|
@@ -1292,7 +1292,8 @@ long keyctl_session_to_parent(void)
|
|
goto not_permitted;
|
|
|
|
/* the keyrings must have the same UID */
|
|
- if (pcred ->tgcred->session_keyring->uid != mycred->euid ||
|
|
+ if ((pcred->tgcred->session_keyring &&
|
|
+ pcred->tgcred->session_keyring->uid != mycred->euid) ||
|
|
mycred->tgcred->session_keyring->uid != mycred->euid)
|
|
goto not_permitted;
|
|
|